如何使用命令模式去调用web服务

//------------------------------------------------------------程序如何实现一个命令模型------------------------------------------------

开始的准备：

[code language="c#"]
private System.ComponentModel.BackgroundWorker worker;

[/code]

1.第一步。也是非常常见的实现btnOK_Click的功能（也就是点击登陆的功能）
                private void btnOK_Click(object sender, EventArgs e)
                {
                        this.Login();
                }
2.第二步。实现Login（）函数
                 private void Login()
                {
                        string[] credential = new string[] { txtUserName.Text, txtPassword.Text };

lblProgress.Visible = true;
lblProgress.Refresh();

loginProgress.Visible = true;
loginProgress.Value = loginProgress.Minimum;

                        worker.RunWorkerAsync(credential);   //这里采用BackGroundWork，去了解这个控件，到这一步的时候，它会去执行DoWork这个操作
                }
3。第三步：实现DoWork函数
                private void worker_DoWork(object sender, DoWorkEventArgs e)
                {
                        // This method will run on a thread other than the UI thread.
                        // Be sure not to manipulate any Windows Forms controls created
                        // on the UI thread from this method.

                        string[] credential = (string[])e.Argument;
                        string userName = credential[0];
                        string password = credential[1];

                        this.Authenticate(userName, password); //这里我们调用验证函数
             }
4.第四步： //在改使用类下新建函数来进行使用该验证
                private void Authenticate(string userName, string password)
                {
                        AuthenticateCommand command = new AuthenticateCommand(userName, password); //注意这里，这里我们已经去调用命令模式里面的东西了
                        ((ICommand)command).Execute(); //执行操作

                        worker.ReportProgress(1, "Loading...");
                }
5.第五步： //这是命令模式里面的东西。。。。
                public class AuthenticateCommand : ICommand
                        {
                public AuthenticateCommand( string userName, string password )
                                {
                                        this._UserName = userName;
                                        this._Password = password;
                                }

                                void ICommand.Execute()                            //this is user for Execute The Application
                                {
                                        UserInfo user = _Application.Settings.UserInfo;   //这个是在ObjectModel里面建立的模型
                                        user.UserName = this._UserName;
                                        string passwordHash = HashStringMD5(this._Password);
                                        user.UserPassword = passwordHash;

                                        using (SecurityService service = ServiceProxyFactory.GetSecurityService())
                                        {
                                user.SecurityKey = service.AuthenticateUser();    //这里才是关键，归根到底是调用WebService的

                                if (null != user.SecurityKey && user.SecurityKey.Length > 0)
                                {
                                    this._IsSuccess = true;
                                }

                                        }
                                }
                       }
//------------------------------------------------------------------------------------------the eth-----------------------------------------------